Peter Robinson has hit out at the Ministry of Defence (MoD) over the length of time taken to respond to an inquiry from his office.
The First Minister told MLAs he requested information about St Lucia barracks in Omagh almost a year ago but has yet to hear anything back.
He said: "Some members in this house think that OFMDFM (Office of First and Deputy First Minister) is slow in getting replies out. Well, meet the MoD.
"W e are still waiting for our reply from last November."
The DUP leader was speaking during Question Time at the Assembly.
He said outstanding legal issues around the ownership of the derelict barracks had to be resolved before development of the huge site could commence.
Mr Robinson said: "The first requirement is for the MoD to resolve the legal issues as to whether the previous owner wants to take the site back into ownership or whether it is free for the MoD to transfer."
It was revealed Omagh District Council, the Department of Social Development and elements from the private sector were interested in developing all or parts of the former military base which closed in 2007.
Mr Robinson said a partnership between the public and private sector may be arranged but, added: "We have to get over the first impediment".
In answer to a separate question about the former Shackleton military base in Co Londonderry, the First Minister said between 1,000 and 2,000 new jobs could be created as part of its redevelopment.
He said OFMDFM had received more than 40 expressions of interest in the site at Ballykelly including from the Department of Regional Development, the Department of Agriculture and a number of different private sector investors which could generate "significant income" for the Executive.